Method and apparatus for identifying the opening state of a garage door

ABSTRACT

A method and a device for detecting the opening state of a garage door or the like, such as a door that restricts entry by a vehicle are provided. A control apparatus generates a predetermined light pattern. A headlight apparatus projects the predetermined light pattern onto the door, while a camera apparatus detects the light pattern projected onto the door. The control apparatus compares the light pattern detected by the camera apparatus with the predetermined light pattern and outputs information signals according to the differences between the detected light pattern and the predetermined light pattern. The differences determine the opening state of the door.

BACKGROUND AND SUMMARY OF THE INVENTION

Exemplary embodiments of the invention relate to a method and a devicefor detecting the opening state of a garage door or the like, such as adoor that restricts entry by a vehicle.

The opening state of garage doors cannot be reliably detected using theultrasound sensors of parking systems that are installed in conventionalvehicles, for example in cars. Although ultrasound sensors have a rangeof approximately 1 m in normal driving operation and a range ofapproximately 5-6 m at low speeds, as are common when parking, they onlyprovide reliable feedback up to a height of approximately 50 cm due totheir installation height in parking systems. In particular forautomated parking, however, it is very important to determine whether agarage door is open wide enough for the vehicle to drive into the garagewithout being damaged.

Cameras which detect the road in front of the vehicle in drivingoperation and, for example, record the road markings or road signs areincreasingly also being used in vehicles. These conventional camerashave difficulty correctly classifying the door, i.e., recognizing it asa garage door and recognizing the opening state thereof.

For example, radar sensors used for measuring the distance from thevehicle in front provide inaccurate results for garage doors due toreflections from the open space behind the door, or do not provide anecho of the radio waves emitted by the radar that can be definitivelylocated.

A LiDAR, in which laser beams are used for optical distance measurement,usually does not provide a large enough opening angle, meaning that itlikewise has significant limitations for detecting doors that openupwards.

Using conventional techniques, the opening state of garage doors thatopen upwards can only be unreliably determined. For example, it is alsodifficult to detect if a garage door has stopped halfway up and is thuspreventing entry. Doors which slide sideways and are not solid maylikewise provide an unreliable echo.

In this context, reference may also be made to US 2014/0118111 A1. Thisdocument describes an alarm system which alerts the person responsibleto close the garage again if a door is unintentionally open. Here,various physical methods are described for identifying the open door.They are based, for example, on a change in the brightness and noiselevel when the door is open compared with when the door is closed, on anRFID chip on the door or on an image comparison of the stored image ofthe open door and the closed door. These methods require a complexapparatus and/or can only be used for the specific known door. Otherprinciples measure the distance between the door and the parked vehicleusing a laser or ultrasound. They are more flexible in relation to thedoor, but like the above-mentioned method involve the problem wherebythey cannot detect a half-open door or non-solid doors, such as gates.

Systems with which the region in front of a vehicle can be illuminatedby means of headlights are known from the prior art.

DE 10 2011 119923 A1 discloses an intelligent lighting system intendedto act as a navigation and operating aid for vehicles. In this system,the dimensions and the radii of action of the vehicle and the componentsthereof are projected directly onto the road in addition to the normalillumination. This visualization of the vehicle width is intended tocreate a kind of warning system, which is also intended to be helpfulfor narrow thoroughfares, such as gateways and garage entrances. Oncethe boundary beams are visible on the entry boundary, for example thewalls to the left and right of a garage door, this indicates a potentialcollision to the driver of the vehicle. However, this known lightingsystem does not make it possible to detect the opening state of a garagedoor, since the vehicle predominantly projects onto the ground in frontof the vehicle. In addition, it is not possible to automatically detectthe opening state using this system.

DE 10 2015 224 792 A1 discloses a method for operating a headlight of amotor vehicle comprising at least one actuatable and light-emittingheadlight element. The headlight element of the headlight generates alight distribution that is monitored by a camera. The camera generatesimage data, by means of which an actual operating state of the headlightis determined. An existing functional limitation of the headlight isdetermined from the deduced actual operating state compared with anintended target operating state. The camera is integrated in the motorvehicle and is arranged behind the windscreen of the motor vehicle, and,for example, is integrated in a rearview mirror device. Using the knownmethod, reduced functionality of a headlight element can be determinedduring the journey and appropriate measures can be taken. However, thisknown method does not make it possible to detect the opening state of agarage door, since only the headlight itself is monitored with regard toits functionality.

The two Chinese documents CN 105 222 752 A and CN 203 094 055 U describemethods in which unevenness in the surface of a road can be detected bymeans of a line pattern projected onto the road. This is advantageous inthat a 3D image of the road surface can ultimately be produced usingimages taken by a 2D camera.

Reference can also be made to DE 103 36 681 A1 as additional prior art,which document describes a method for the targeted illumination of anobject detected in the surroundings of a vehicle. A complex headlight isused for this purpose, which is capable of directing its light beamtowards the object to be illuminated in a targeted manner.

The problem addressed by the present invention is that of providing amethod and a device that make it possible to reliably detect the openingstate of a garage door or the like, such as a door that restricts entryby a vehicle.

In the method, a predetermined light pattern is accordingly generatedand projected onto the door. The light pattern projected onto the dooris detected and compared with the predetermined light pattern.Information signals are generated according to the differences betweenthe detected light pattern and the predetermined light pattern, thedifferences determining the opening state of the door. Using the methodaccording to the invention, by projecting and observing light patternson the door to be detected, it is possible to detect, in a simplemanner, whether the door is closed, partially open or completely open.In this case, a predetermined pattern is compared with the pattern thatis actually detected.

In order to identify partially open regions of the door, regions of thedetected light pattern can be detected that have changed compared withthe predetermined light pattern. In this case, parts of thepredetermined light pattern in the at least partially open regions donot appear, do not completely appear, or appear distorted in thedetected or observed light pattern, since here the predetermined lightpattern is not projected onto part of the garage door.

In this case, the predetermined light pattern has an array of identicallight objects that have the same geometry and surface area. Thisarrangement makes it possible to easily compare the predetermined lightpattern with the detected light pattern, since differences are clearlyvisible.

The opening process of the door can also be detected by detecting thelight pattern projected onto the door and comparing the detected lightpattern with the predetermined light pattern continuously or repeatedly.A change in the number of detected light objects and the surface areasof the light objects is analyzed over time here.

In the device, a control apparatus is provided for generating apredetermined light pattern and a headlight apparatus is provided forprojecting the predetermined light pattern onto the door. A cameraapparatus detects or observes the light pattern projected onto the door.The control apparatus compares the light pattern detected by the cameraapparatus with the predetermined light pattern and outputs informationsignals according to the differences between the detected light patternand the predetermined light pattern, the differences determining theopening state of the door. Using the device according to the invention,by projecting and observing light patterns on the door to be detectedand on the space therebehind, it is possible to detect, in a simplemanner, whether the door is closed, partially open or completely open.In this case, a predetermined pattern is compared with the pattern thatis actually detected.

According to a preferred embodiment, the headlight apparatus maycomprise at least one projection-enabled headlight in the form of agrid-like light source or the like equipped with LED chips that can beindividually actuated by the control apparatus. A headlight of this typeis also known as a multibeam LED headlight, which can project a focusedlight pattern onto a surface, for example a garage door. What are knownas laser headlights can also be used. This light pattern can be easilydetected by the camera apparatus and can be easily processed in thecontrol apparatus, meaning that the distance from the projection surfacecan be reliably determined.

In a further embodiment, the headlight apparatus may comprise infrareddiodes (IR diodes) and the light pattern may be projected in theinfrared wavelength range. IR light is invisible to the human eye, andtherefore the opening state of the door can be detected without beingnoticed by observers, and also nobody is dazzled unnecessarily.Alternatively, what is known as a time of flight (TOF) measurement is,for example, also possible using a TOF camera, in which a propagationtime technique is carried out by means of laser scanning, similarly to aFlash LiDAR.

A display apparatus may be provided inside the vehicle on which theopening state of the door is displayed to the driver of the vehiclebased on the information signals generated by the control apparatus.This may be acoustic and/or graphic. Here, the display device assiststhe driver when parking in the garage and/or when driving through thedoor.

In another, advantageous embodiment, the control apparatus may beconnected to a fully or partially automatic parking system of thevehicle. Based on the information signals generated by the controlapparatus, the opening state of the door may be used for controlling theprocess of parking the vehicle. For example, by means of what is knownas a remote parking pilot, a vehicle equipped with ultrasound parkingsensors can be parked remotely using a smartphone. For this remoteparking in a garage, it is important that the system takes into accountthe opening state of the garage door.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Further advantageous embodiments of the method and the device accordingto the invention become clear on the basis of an embodiment that isdescribed in greater detail with reference to the drawings, in which:

FIG. 1 is a schematic side view of a vehicle that is positioned in frontof a garage door and is equipped with a device for detecting the openingstate of the garage door according to an embodiment of the invention;

FIG. 2 is a schematic plan view of the vehicle that is positioned infront of the garage door and shown in FIG. 1;

FIG. 3 is a schematic front view of the garage door shown in FIGS. 1 and2 when completely closed, with a predetermined light pattern beingprojected onto the garage door; and

FIG. 4 is a schematic front view of the garage door shown in FIGS. 1 to3 when partially open, having a light pattern that has changed comparedwith the predetermined light pattern.

DETAILED DESCRIPTION

FIG. 1 is a schematic side view of a vehicle 6 that is positioned infront of a garage door 8 and is equipped with a device (described ingreater detail in the following) for detecting the opening state of thegarage door according to an embodiment of the invention.

A headlight apparatus 14 of the vehicle 6 projects a predetermined lightpattern, schematically shown in FIG. 1 by the beam of light havingreference sign 10, onto the door 8 of a garage (not shown in greaterdetail). The door 8 is closed. The predetermined light pattern 10 iscompletely projected onto the closed door 8 and generates a projectedlight pattern 20.

The predetermined light pattern 10 is generated by a control apparatus12 that is connected to the headlight apparatus 14 by means of a vehiclebus and is built into the vehicle 6. The control apparatus 12 is acomputer on board the vehicle having corresponding graphics properties.

A camera apparatus 18 connected to the vehicle bus is arranged behindthe windshield in the region of the rearview mirror device of thevehicle 6 and detects or records the light pattern 20 projected onto thedoor 8.

The control apparatus 12 compares the light pattern 20 detected by thecamera apparatus 18 with the predetermined light pattern 10. Since thedoor 8 is closed, the camera records the entire projected light pattern20, which corresponds to the predetermined light pattern 10. Based onthis comparison result, the control apparatus 12 generates acorresponding information signal with the value “Door closed”. Thisinformation is displayed to the driver of the vehicle 6 on a displayapparatus 24 that is connected to the vehicle bus and is positionedinside the vehicle 6. The display apparatus 24 is the screen of a driverinformation system built into the vehicle 6.

According to an alternative embodiment (not shown), the controlapparatus 12 may be connected to a fully or partially automatic parkingsystem of the vehicle 6. The information signals regarding the openingstate of the door 8 can then be used for controlling the process ofparking the vehicle 6.

FIG. 2 is a schematic plan view of the vehicle 6 that is positioned infront of the garage door 8 and shown in FIG. 1.

The headlight apparatus comprises two LED headlights 14 and 16 of aMULTIBEAM LED lighting system. The LED headlights 14 and 16 of theMULTIBEAM LED lighting system each comprise a very rapidly reactingprecision illumination module in the form of a grid-like light source,which is equipped with 24 individual high-power LED chips. Each of theseLED chips can be actuated by the control apparatus 12 electronically andindependently of the others. Therefore, the control apparatus 12controls the LED chips of the headlights 14 and 16 according to thepredetermined light pattern 10. The headlight 14 on the right-hand sidein the travel direction of the vehicle 6 generates a predeterminedpartial light pattern 10 a and the headlight 16 on the left-hand side inthe travel direction of the vehicle 6 generates a predetermined partiallight pattern 10 b. Overlaying the two partial light patterns 10 a and10 b produces the predetermined light pattern 10 that is projected ontothe garage door 8, which is closed in FIGS. 1 and 2, and generates theprojected light pattern 20 thereon.

According to an alternative embodiment (not shown), just one of theheadlights 14 or 16 can be used for projecting the light pattern 20. Thepredetermined light pattern 10 is then not generated by two partiallight patterns.

According to another alternative embodiment (not shown), the headlights14 and 16 may comprise infrared diodes (IR diodes) that project thelight pattern in the infrared wavelength range.

According to another alternative embodiment (not shown), the lightpattern may be projected onto the garage door by an additional lightsource, for example a third searchlight or a separate laser scanner.

FIG. 3 is a schematic front view of the garage door 8 shown in FIGS. 1and 2 when completely closed, with the predetermined light pattern 10being projected onto the garage door 8.

The predetermined light pattern 10 generated by the control apparatus 12consists of an array of twelve identical, rectangular light objects 22having the same surface area. The rectangles are arranged in columns androws in accordance with the array. The headlights 14 and 16 project thepredetermined light pattern 10 onto the closed garage door. The lightpattern 20 projected onto the closed garage door 8 corresponds to thepredetermined light pattern 10.

The camera apparatus 18 detects the light pattern 20. The controlapparatus 12 compares the light pattern 20 detected by the cameraapparatus 18, in particular the distribution, number and surface areasof the rectangular light objects 22, with those of the predeterminedlight pattern 10. Since the door 8 is closed in FIG. 3, the camerarecords the entire projected light pattern 20. The distribution, numberand surface areas of the rectangular light objects 22 of the projectedlight pattern 20 corresponds to the distribution, number and surfaceareas of the rectangular light objects 22 of the predetermined lightpattern 10.

On the basis of this comparison result, the control apparatus 12generates the information signal with the value “Door closed”, which isdisplayed to the driver of the vehicle 6 on the display apparatus 24.

FIG. 4 is a schematic front view of the garage door 8 shown in FIGS. 1to 3 when partially open, having a light pattern 20 that has changedcompared with the predetermined light pattern 10.

The headlights 14 and 16 project the predetermined light pattern 10 ontothe partially open garage door 8. The light pattern 20 projected ontothe partially open garage door 8 does not correspond to thepredetermined light pattern 10. Instead, there are differences in theopen region B of the garage door when comparing the two light patterns10 and 20.

The camera apparatus 18 detects the light pattern 20 projected onto thepartially open garage door 8. The control apparatus 12 compares thelight pattern 20 detected by the camera apparatus 18, in particular withregard to the distribution, number and surface areas of the rectangularlight objects 22 of the two light patterns 10 and 20.

Since the door 8 is partially open in FIG. 4, the camera records anentire light pattern 20 projected onto the garage door 8 that differsfrom the predetermined light pattern 10 radiated by the headlights 14and 16. The distribution, number and surface areas of the rectangularlight objects 22 of the projected light pattern 20 does not correspondto the distribution, number and surface areas of the rectangular lightobjects 22 of the predetermined light pattern 10. Instead, only nine ofthe original twelve rectangular light objects 22 are visible in theupper part of the projected light pattern 20. The lower part, which isformed by the region B in FIG. 4, does not comprise any light objects.Instead, the three light objects 22′ arranged in a row in the bottompart of the garage door closest to the open region B are partially cutoff, and thus have a reduced surface area that differs from thepredetermined light pattern 10.

Based on this comparison result, the control apparatus 12 generates theinformation signal with the value “Door partially open”, and, using themeasurement of the region B, how far the garage door 8 is open can alsobe specified. This information is displayed to the driver of the vehicle6 on the display apparatus 24.

For a garage door that is completely open (not shown), the cameraapparatus 18 together with the control apparatus 12 does not detect anylight objects 22 in the projected light pattern 20. Based on thiscomparison result, the control apparatus 12 generates the informationsignal with the value “Door completely open”. This information isdisplayed to the driver of the vehicle 6 on the display apparatus 24.

The light pattern 20 projected onto the door 8 is detected and thedetected light pattern 20 is compared with the predetermined lightpattern 10 continuously or at timed intervals, as a result of which anopening process of the door 8 is detected. A change in the number ofdetected light objects 22 and the surface areas of the light objects 22′is continuously analyzed and displayed to the driver.

Although the invention has been illustrated and described in detail byway of preferred embodiments, the invention is not limited by theexamples disclosed, and other variations can be derived from these bythe person skilled in the art without leaving the scope of theinvention. It is therefore clear that there is a plurality of possiblevariations. It is also clear that embodiments stated by way of exampleare only really examples that are not to be seen as limiting the scope,application possibilities or configuration of the invention in any way.In fact, the preceding description and the description of the figuresenable the person skilled in the art to implement the exemplaryembodiments in concrete manner, wherein, with the knowledge of thedisclosed inventive concept, the person skilled in the art is able toundertake various changes, for example, with regard to the functioningor arrangement of individual elements stated in an exemplary embodimentwithout leaving the scope of the invention, which is defined by theclaims and their legal equivalents, such as further explanations in thedescription.

The invention claimed is:
 1. A method for detecting the opening state ofa door that restricts entry by a vehicle, the method comprising:generating a predetermined light pattern having an array of identicallight objects with a common geometry and surface area, wherein the arrayof identical light objects includes the identical light objects beingarranged in columns and rows and each of the identical light objects ofthe array of identical light objects are spaced apart from adjacentidentical light objects in both the columns and rows of the array ofidentical light objects so that no light is generated between adjacentidentical light objects of the array of identical light objects;projecting the predetermined light pattern onto the door; detecting thelight pattern projected onto the door; comparing the detected lightpattern with the predetermined light pattern to determine whether thedoor is open or closed; and generating information signals correspondingto an opening state of the door according to differences between thedetected light pattern and the predetermined light pattern identified inthe comparison.
 2. The method of claim 1, wherein comparing the detectedlight pattern with the predetermined light pattern comprises: detectingregions of the detected light pattern that have changed compared withthe predetermined light pattern, the detected regions being identifiedas at least partially open regions of the door.
 3. The method of claim1, wherein detecting the light pattern projected onto the door andcomparing the detected light pattern with the predetermined lightpattern takes place continuously or repeatedly, as a result of which anopening process of the door is detected by analyzing a change in anumber of detected light objects of the detected light pattern, surfaceareas of the detected light objects of the detected light pattern, or acontour of the detected light objects of the detected light pattern. 4.A device for detecting the opening state of a door that restricts entryby a vehicle, the device comprising: a controller configured to generatea predetermined light pattern having an array of identical light objectswith a common geometry and surface area, wherein the array of identicallight objects includes the identical light objects being arranged incolumns and rows and each of the identical light objects of the array ofidentical light objects are spaced apart from adjacent identical lightobjects in both the columns and rows of the array of identical lightobjects so no light is generated between adjacent identical lightobjects of the array of identical light objects; a headlight configuredto project the predetermined light pattern onto the door; and a cameraconfigured to detect the light pattern projected onto the door, whereinthe controller is configured to compare the light pattern detected bythe camera with the predetermined light pattern and output informationsignals corresponding to an opening state of the door according todifferences between the detected light pattern and the predeterminedlight pattern.
 5. The device of claim 4, wherein the headlight comprisesat least one a grid light source with LED chips that can be individuallyactuated by the controller.
 6. The device of claim 4, wherein theheadlight comprises infrared diodes and the light pattern is projectedin an infrared wavelength range.
 7. The device of claim 4, furthercomprising: a display arranged inside the vehicle and configured todisplay the opening state of the door based on the information signals.8. The device of claim 4, wherein the controller is connected to a fullyor partially automatic parking system of the vehicle and the openingstate of the door is used for controlling the process of parking thevehicle based on the information signals.
 9. The method of claim 1,wherein, responsive to the comparison of the detected light pattern withthe predetermined light pattern indicating that at least a portion of atleast one of the identical light objects is not present in the detectedlight pattern, the generated information signals indicate that the dooris at least partially open.
 10. The device of claim 4, wherein thecontroller, responsive to the comparison of the detected light patternwith the predetermined light pattern indicating that at least a portionof at least one of the identical light objects is not present in thedetected light pattern, determines that the door is at least partiallyopen.